﻿#region COPYRIGHT
//--------------------------------------------------------------------------------
// <copyright file="DiscRegion.cs" company="starLiGHT Entertainment Studios">
//    Copyright (c) 2008, 2009, 2010, 2011
//       Roland Rosenkranz (Glatzemann@email.de)
// </copyright>
// <license>
//   This file is part of starLiGHT.Particles.
//
//   starLiGHT.Particles is free software: you can redistribute it and/or modify
//   it under the terms of the GNU Lesser General Public License as published by
//   the Free Software Foundation, either version 3 of the License, or
//   (at your option) any later version.
//
//   starLiGHT.Particles is distributed in the hope that it will be useful,
//   but WITHOUT ANY WARRANTY; without even the implied warranty of
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//   GNU Lesser General Public License for more details.
//
//   You should have received a copy of the GNU Lesser General Public License
//   along with starLiGHT.Particles. If not, see http://www.gnu.org/licenses/.
//    
//   ADDITIONAL (commercial) LICENSES for starLiGHT.Particles are available on request.
// </license>
// <original_license>
//  * FLINT PARTICLE SYSTEM
//  * .....................
//  * 
//  * Author: Richard Lord
//  * Copyright (c) Richard Lord 2008-2009
//  * http://flintparticles.org
//  * 
//  * 
//  * Licence Agreement
//  * 
//  * Permission is hereby granted, free of charge, to any person obtaining a copy
//  * of this software and associated documentation files (the "Software"), to deal
//  * in the Software without restriction, including without limitation the rights
//  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  * copies of the Software, and to permit persons to whom the Software is
//  * furnished to do so, subject to the following conditions:
//  * 
//  * The above copyright notice and this permission notice shall be included in
//  * all copies or substantial portions of the Software.
//  * 
//  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  * THE SOFTWARE.
// </original_license>
// <version>
// **************[ starLiGHT.Engine SVN ]**********************
// * $Rev::                       $:  Revision of last commit *
// * $Author::                    $:  Author of last commit   *
// * $Date::                      $:  Date of last commit     *
// ************************************************************
// </version>
//--------------------------------------------------------------------------------
#endregion

namespace starLiGHT.ParticleSystem.twoD
{
    #region Using Statements
    using System;
    using System.Collections.Generic;
    using System.Text;
    using Microsoft.Xna.Framework;
    using starLiGHT.ParticleSystem.Common;

    #endregion

    public class DiscRegion : IRegion2D
    {
        private Vector2 center;
        private float innerRadius;
        private float outerRadius;
        private float innerSq;
        private float outerSq;
        private System.Random random = new System.Random();

        public DiscRegion()
            : this(Vector2.Zero, 0, 0)
        {
        }

        public DiscRegion(Vector2 center, float outerRadius, float innerRadius)
        {
            if (outerRadius < innerRadius)
            {
                throw new Exception("The outerRadius (" + outerRadius + ") can't be smaller than the innerRadius (" + innerRadius + ") in your DiscRegion. N.B. the outerRadius is the second argument in the constructor and the innerRadius is the third argument.");
            }

            this.center = center;
            this.innerRadius = innerRadius;
            this.outerRadius = outerRadius;
            this.innerSq = this.innerRadius * this.innerRadius;
            this.outerSq = this.outerRadius * this.outerRadius;
        }

        public Vector2 Center
        {
            get { return this.center; }
            set { this.center = value; }
        }

        public float InnerRadius
        {
            get 
            { 
                return this.innerRadius; 
            }

            set
            {
                this.innerRadius = value;
                this.innerSq = this.innerRadius * this.innerRadius;
            }
        }

        public float OuterRadius
        {
            get 
            { 
                return this.outerRadius; 
            }

            set
            {
                this.outerRadius = value;
                this.outerSq = this.outerRadius * this.outerRadius;
            }
        }

        public bool contains(Vector2 pos)
        {
            pos -= center;
            float distSq = pos.X * pos.X + pos.Y * pos.Y;
            return distSq <= this.outerSq && distSq >= this.innerSq;
        }

        public Vector2 getLocation()
        {
            float rand = (float)random.NextDouble();
            Vector2 point = polar2cartesian(Vector2.Zero, this.innerRadius + (1 - rand * rand) * (this.outerRadius - this.innerRadius), (float)(random.NextDouble() * MathHelper.TwoPi));

            point += center;

            return point;
        }

        public float getArea()
        {
            throw new NotImplementedException();
        }

        private Vector2 polar2cartesian(Vector2 v, float dist, float bearing)
        {
            v.X = (float)(v.X + dist * Math.Sin(bearing));
            v.Y = (float)(v.Y + dist * Math.Cos(bearing));

            return v;
        }
    }
}
